High-Performance Computing

For many applications, the data one needs to cope with for a major scientific innovation or discovery is immense, distributed, and unstructured. Thanks to the advancements on computer hardware and storage technologies, we currently have good arsenals to manage it. However, not every hardware-algorithm combination is effective and efficient enough to provide an insight that can make an impact on science, technology, and hence, on the public. And even with the best combination at hand, the performance we settle for today will not be sufficient in the future since the data growth is exponential; around 90% of the data we have is generated in the last two years.

Efficiency is not only a concern when the data is large: for time-critical applications, one needs to utilize the architecture at hand as efficient as possible. Today’s architectures are driven by power limitations; instead of using a single, very fast, power-hungry core, the CPUs we currently use have relatively slower cores. To get further computing power within a reasonable power envelope, accelerators have been developed by packing much simpler cores into a single die. Today, the world's most powerful supercomputers contain heterogeneous nodes which are equipped with cutting-edge multicore CPUs, faster SSDs, as well as accelerators, such as GPUs with thousands of cores or Intel's Xeon Phi. Due to this heterogeneity, applying different parallelization techniques at different levels of hardware/software is a necessity to achieve the peak performance and fully utilize such architectures. At Sabancı University, we conduct HPC research on social network analysis, combinatorial algorithms for scientific computing and runtime middleware systems for emerging multi-core architectures.

• Application mapping on different levels of a hierarchical parallel computing system.

  GPUs and accelerators are being deployed in the Cloud to improve processing capabilities and provide heterogeneity as Cloud Computing Systems become increasingly complex and process ever-increasing datasets. In such systems, application scheduling and data mapping need to be enhanced to maximize the utilization of the underlying architecture. Cloud management schemes require a fresh look when the underlying components are heterogeneous to achieve this. Moreover, applications differ in the way they perform on various special accelerators.

  Manycore accelerators are widely used in many contemporary systems. In such systems, application mapping needs to be enhanced to maximize the utilization of the underlying architecture. Especially in GPUs, mapping becomes critical for multi-kernel applications as kernels may exhibit different characteristics. While some kernels run faster on GPU, others may stay on CPU due to the high data transfer overhead. Thus, heterogeneous execution may yield improved performance compared to executing the application only on the CPU or GPU.